1. Field of the Invention:
The present invention relates generally to tapering machines, and more particularly, is directed to a machine capable of field tapering the ends of fiberglass pipe for connection with the factory tapered sections of connected couplings, fittings and nipples.
2. Description of the Prior Art:
In the automotive service station industry, it is the usual practice to provide a plurality of approved underground storage tanks of various sizes in approved underground locations for storage and subsequent dispensing of gasoline and other types of flammable liquids. Such underground flammable liquid storage tanks are generally fabricated either of steel or fiberglass construction materials to meet local regulations and industry standard, such as N.F.P.A. Pamphlet 30. It is the common practice to install the underground storage tanks in multiples or banks beneath the driveway surface and each tank requires the usual piping connections. The storage tanks are interconnected by piping with each other and with pluralities of above ground gasoline dispensing units for ultimate vending or dispensing into the tanks of automobiles. Additionally, each tank must be equipped with suitable fill and vent pipes for safe operation. The dispensing units are generally employed in multiple arrangements and are usually mounted on one or more service islands in accordance with the usual practice in the industry.
In the past, it was most common to employ conventional steel piping between the underground storage tanks and the dispensing units mounted upon the service islands. More recently, fiberglass reinforced epoxy piping has been developed and has gained authority approval and increasing popularity for such underground piping systems. One fiberglass reinforced epoxy pipe which has been listed by Underwriters' Laboratories, Inc. as meeting the standards set forth in NFPA Pamphlet 30 has been developed and sold by Fiberglass Pipe Division, Houston, Tex. under the trademark "AMERON". Other fiberglass pipe manufacturers include A. O. Smith-Island, Inc. and Ciba-Geigy.
When employing the approved fiberglass pipe for automotive service station installations, it is practically always necessary to cut a considerable portion of such pipes to size directly at the jobsite to meet the existing local conditions. The interconnection between the ends of lengths of pipe and fittings in the listed fiberglass piping systems is always made by tapering the interior cavity of the fitting and by providing a cooperating taper in the exterior periphery of the pipe end. In the approved fiberglass pipe systems, the fittings and couplings are tapered at the factory with a uniform 13/4 degree taper for all usual pipe diameters from 2 inches through 6 inches pipe size. The taper length varies from 11/2 inches for 2 inch diameter pipe up to 23/4 inches for 6 inch diameter pipe.
It will be appreciated that the taper of the pipe end must correspond substantially identically to the factory made taper in the connecting fittings and couplings to prevent leakage and these precise tapers must be field made in those fiberglass pipe sections which have been duly cut to the required length at the installation site. After the tapers of the required angularity have been formed in the pipe ends (either at the factory or in the field), the joint is made up in a leak-proof junction by employing a coating of an approved adhesive.
Prior workers in the art have developed field tapering equipment which is designed to cut the required 11/2 degree taper on the 2 inch through 6 inch pipe ends. Such prior art field tapering machines have usually utilized shaving blades and the like and such machines as previously developed have generally proved to be satisfactory for providing the required pipe end taper of the necessary angularity. However, such prior art machines have suffered from drawbacks such as significantly high costs and the fact that such machines offer little or no safety to the user from the environmental problems created by the cutting, shaving and other operations which may be necessary to effect the pipe end taper. Keeping in mind the fiberglass content of the piping materials, it will be appreciated that when such fiberglass is broken down into fine particles by the cutting, shaving and other operations, such fine particles could be extremely injurious and dangerous to the health of the user.
Accordingly, it is now the common practice to require or recommend that the field pipe end tapering machine users employ dust masks over their faces when using the existing pipe tapering machines to properly form the required taper. While such masks will to a large extent alleviate the fiberglass dust problem, such masks are not one hundred percent effective under usual working conditions. Additionally, some workers either carelessly or defiantly will often neglect wearing the face masks, thereby subjecting themselves to the dangers of inhaling fiberglass dust and particles.